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Briefly discusses kava (also known as kava kava), a dietary supplement used to relieve anxiety, restlessness, insomnia, and stress-related symptoms. Covers safety issues and side effects, including liver damage in some when used for long periods.

Kava

Topic Overview

What is kava?

Kava—or kava kava—is a root found
on South Pacific islands. Islanders have used kava as medicine and in
ceremonies for centuries.

Kava has a calming effect, producing
brain wave changes similar to changes that occur with calming medicines such as
diazepam (Valium, for example). Kava also can prevent convulsions and relax
muscles. Although kava is not addictive, its effect may decrease with
use.

Traditionally prepared as a tea, kava root is also available
as a dietary supplement in powder and tincture (extract in alcohol)
forms.

What is kava used for?

Kava's calming effect may relieve anxiety, restlessness, sleeplessness, and
stress-related symptoms such as muscle tension or spasm. Kava
may also relieve pain.

When
taken for anxiety or stress, kava does not interfere with mental sharpness.
When taken for sleep problems, kava promotes deep sleep without affecting
restful REM sleep.

Kava may be used instead of prescription
antianxiety drugs, such as benzodiazepines and tricyclic antidepressants. Kava
should never be taken with these prescription drugs. Avoid using alcohol when
taking kava.

Is kava safe?

Kava may have severe side effects
and should not be used by everyone. Kava has caused liver failure in previously
healthy people. You should not use kava for longer than 3 months without
consulting your doctor.

Before you use kava, consider that
it:

Should not be combined with alcohol or
psychotropic medicines. Psychotropic medicines are used to treat psychiatric
disorders or illnesses and include antidepressants and mood stabilizers.
Alcohol exaggerates kava's sedating effect.

Can affect how fast you react, making it unsafe to drive or use
heavy machinery.

May gradually be less powerful as you use
it.

Eventually may cause temporary yellowing of skin, hair, and
nails.

Can cause an allergic skin reaction (rare).

Long-term kava use may result in:

Liver problems.

Shortness of
breath (reversible).

Scaly rash (reversible).

Facial
puffiness or swelling (reversible).

The U.S. Food and Drug Administration (FDA) has
investigated whether using dietary supplements containing kava is associated
with liver illness. Reports from Germany and Switzerland about kava causing
serious liver problems have led to the recent removal of these products from
shelves in Britain. Other countries have advised consumers to avoid using kava
until further information is available.

In the United States, the
FDA advises people who have liver disease or liver problems, or people who are
taking medicines that can affect the liver, to consult a doctor or pharmacist
before using products that contain kava. People who use a dietary supplement
that contains kava and experience signs of illness should consult a doctor.
Symptoms of serious liver disease include brown urine as well as yellowing of
the skin or of the whites of the eyes. Other symptoms of liver disease may
include nausea, vomiting, light-colored stools, unusual tiredness, weakness,
stomach or abdominal pain, and loss of appetite.

The FDA does not
regulate dietary supplements in the same way it regulates medicine. A dietary
supplement can be sold with limited or no research on how well it works.

Always tell your doctor if you are using a dietary supplement or if you
are thinking about combining a dietary supplement with your conventional
medical treatment. It may not be safe to forgo your conventional medical
treatment and rely only on a dietary supplement. This is especially important
for women who are pregnant or breast-feeding.

When using dietary
supplements, keep in mind the following:

Like conventional medicines, dietary
supplements may cause side effects, trigger allergic reactions, or interact
with prescription and nonprescription medicines or other supplements you might
be taking. A side effect or interaction with another medicine or supplement may
make other health conditions worse.

The way dietary supplements are
manufactured may not be standardized. Because of this, how well they work or
any side effects they cause may differ among brands or even within different
lots of the same brand. The form of supplement that you buy in health food or
grocery stores may not be the same as the form used in research.

Other than for vitamins and minerals, the long-term effects of
most dietary supplements are not known.

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How this information was developed to help you make better health decisions.